FIG. 11 is a circuit diagram illustrating a conventional three-phase PWM converter. When a three-phase voltage source 12 applies three-phase voltages Va, Vb, Vc to a converter CNV, three-phase currents Ia, Ib, Ic flow to the converter CNV via a group of reactors Z. FIG. 12 is a diagram showing input/output waveforms obtained as a result of simulation in a steady state of the three-phase PWM converter. To set a voltage Vdc at 700 V, the three-phase currents Ia, Ib, Ic flow with a peak value of 12 A.
As a technique pertinent to the present invention, a technique using a PWM (Pulse Width Modulation) power converting apparatus for converting three-phase electric power into two-phase electric power is illustrated in Japanese Patent Application Laid-Open No. 11-018433 and the like.